Method of fabricating inkjet nozzles

1. A method of fabricating inkjet nozzles on a substrate, each nozzle comprising a nozzle chamber and an actuator positioned in the nozzle chamber, each nozzle chamber comprising a roof having a nozzle aperture defined therein and sidewalls extending from the roof to the substrate, the method comprising the steps of:

(a) depositing a layer of first sacrificial material onto the substrate;

(b) defining actuator scaffolds in the first sacrificial material

(c) depositing actuator material onto the actuator scaffolds;

(d) etching the actuator material to define actuators;

(e) depositing a layer of second sacrificial material onto at least one of the substrate, the first sacrificial material and the actuators;

(f) defining openings in the second sacrificial material, the openings being complementary to chamber sidewalls;

(g) depositing roof material onto the second sacrificial material and into the openings, thereby forming the roof and sidewalls of each chamber;

(h) etching nozzle apertures through each roof; and

(i) removing the first and second sacrificial materials exposed through the nozzle apertures.

2. The method of claim 1 , which forms part of a printhead fabrication process.

3. The method of claim 1 , wherein the actuator is a thermal actuator.

4. The method of claim 1 , wherein each chamber roof forms part of a nozzle plate spanning a plurality of nozzles.

5. The method of claim 1 , wherein the roof material is a glass material.

6. The method of claim 1 , wherein the roof material is silicon nitride.

7. The method of claim 1 , wherein the roof material is deposited by plasma enhanced chemical vapour deposition (PECVD).

8. The method of claim 1 , wherein each nozzle aperture has a respective nozzle rim.

9. The method of claim 7 , wherein nozzles rims are etched into each roof prior to etching nozzle apertures through each roof.